Greetings everyone, I'm developing small embedded systems. I can't use Python to program them, I have to program the little CPU's in C.
I want a peripheral I've designed to talk over USB to a Python program on the host computer. The peripheral is spewing data at a reasonably high rate, about 5,000 16-bit unsigned integers per second. For now, I'm trying to print these numbers as they come in. Even though I'm working with a fast, up-to-date computer, I am finding it difficult for the host computer to keep up with the data stream. The details of my setup: running Python 3.4 on Ubuntu 15.04 x64. Using PySerial to handle UART over USB. Intel Core i7-4790K CPU @ 4.00GHz. At first I had the peripheral transmit the numbers as base-10 encoded strings, separated by spaces, just so that I could see that I was receiving the right values from the peripheral. My serial port reads look fine -- until they fall behind. But in this first case, I was using up to six bytes to send a two-byte value. Obviously that's wasteful. So I rewrote the peripheral to send bundles of C uint_16's, with each bundle of three numbers separated by a newline. Now the challenge is to unpack and display those numbers on the Python side. I know that print statements themselves are probably slowing things down, but I still want to see that those numbers are correct. So, how can I take the byte sequence <0x01 0x02 0x03 0x04 0x05 0x06 \n> that Serial.readline() returns to me, and QUICKLY turn it into three integer values, 258, 772, and 1286? Better yet, can I write these bytes directly into an array (numpy is an option), since I'm going to have a lot of them? I never thought I would find a task that's easier for me to imagine doing in C than in Python, but at the moment this is one. Thanks for any suggestions! -- https://mail.python.org/mailman/listinfo/python-list
